1. Field of the Invention
The present invention relates to a switch apparatus for switching a device between ON and OFF states or between functions and, more particularly, to a lighted switch apparatus in which the position or switching state of an operating knob is indicated by a light source provided in the switch apparatus.
2. Description of the Related Art
Conventionally, the mirror switch apparatus has been provided as an example of the lighted switch apparatus, which switches a device between ON and OFF states or between functions and in which the position or switching state of an operating knob is indicated by a light source provided in the switch apparatus. The mirror switch apparatus is used to remotely operate the angles of the left and right mirrors on the vehicle body from the driver's seat by the driving power of the motor.
The mirror switch apparatus has a change-over switch and an angle adjustor switch, both of which are provided in one housing. The change-over switch is used for switching to the left mirror or to the right mirror. The angle adjustor switch has one knob, which can be tilted in any direction for adjusting the tilting angle of the switched mirror in the vertical or horizontal directions.
Such a switch apparatus mounted in a vehicle may be operated in the evening or at night when it is dark out. Accordingly, in dark places, a lighted switch apparatus incorporating an illuminating device is used to permit the driver to know the position and switching state of the switch apparatus. When two switches are built close to each other as in the above-described mirror switch apparatus, there is, in particular, a demand for an illuminating device that easily allows the operator to know the current position of the change-over switch or the vertical or horizontal operating positions even in dark places.
An example of a lighted switch apparatus in the related art is disclosed in JP-A-9-245567 (U.S. Pat. No. 5,813,519), and is shown in FIGS. 7 to 9.
The mirror switch apparatus, in particular, the left and right mirror switch apparatus shown in FIGS. 7 to 9 primarily includes an upper case 201 with an open bottom, an operating knob 202 for selectively controlling left and right mirror driving motors (not shown), a light-guiding member 203 for guiding light to the operating knob 202, a circuit board 204 having, for example, a pattern of a plurality of stationary contacts printed thereon, and a lower case 205 which is a cover for securing the light-guiding member 203 and the circuit board 204 along with the upper case 201.
The upper case 201 has an opening 201a formed in its top surface for inserting therein the bottom of the operating knob 202 of a slide switch portion, a pair of light-intercepting portions 201b formed on both sides of the opening 201a so as to extend in the sliding direction of the operating knob 202, and side faces 201c formed from each of the side edges of the top surface. A pair of engaging recesses 201d are provided with a predetermined interval at the bottom of each of opposing side surface 201c on one side of the side surface 201c of the upper case 201.
The operating knob 202 is disposed above the top surface of the upper case 201 and is slidably fitted into the opening 201a of the upper case 201 in the longitudinal direction. The center of top face of the operating knob 202 is formed as a knob portion 202a which the operator moves with his fingers when operating the knob. Transparent indicators 202b, molded from two components, are formed on both sides of the knob portion 202a in the sliding direction in the form of arrows, characters, and symbols indicating directions. A square-shaped cylindrical connector is projected in the center of the lower surface of the operating knob 202, and engaging recesses 202c are formed at the opposing walls of the connector.
A slider member 206, integrally formed with the operating knob 202, is slidably accommodated in the upper case 201. The operating knob 202 and the slider member 206 form the slider. The slider member 206 is made of transparent synthetic resin and has a connector 206a projecting from the center of the top surface of the slider member 206. The connector 206a of the slider member 206 is inserted into the opening 201a of the upper case 201 and fitted to the connector of the operating knob 202. An engaging protrusion 206b of the connector 206a of the slider member 206 engages the engaging recesses 202c of the operating knob 202, whereby the operating knob 202 and the slider member 206 are snap-fitted with each other. Gaps are formed between the bottoms of the indicators 202b of the operating knob 202 and the slider member 206 for placing the light-intercepting portions 201b of the upper case 201 therein. Accordingly, when the operating knob 202 is moved in a reciprocating fashion along the opening 201a from above the upper case 201, the slider member 206 also reciprocates in the same direction. The length of the slider member 206 in the direction of movement is such that when the slider member 206 is moved in one direction and the connector 206a engages one end of the connector 206a, the portion on the other side of the connector 206a located on the starting end of the sliding movement is located below the opening 201a. In addition, as shown in FIG. 9, two rectangular recesses 206c are formed in a side face extending in a direction perpendicular to the direction of movement of the slider member 206, with the recesses 206c formed substantially horizontally and being separated by a distance equal to the thick-walled portion of the knob portion 202a. The ends of the two recesses 206c incline upward from the bottom to the top, so that light, coming from a side face opposing the side face in which the openings of the recesses 206c are formed, is reflected upward by inclined reflecting surfaces 206d. Spaced movable contact accommodating recesses 206e are formed at both ends of the lower face of the slider member 206, and accommodate flat movable contacts (not shown), respectively. In the slider member 206, a ball operates to elastically press-contact against the side face 201c of the upper case 201 by the ball and a spring (not shown) in order to retain the operating knob 202 in the two switching positions and the neutral position so as to cause the operator to feel a click.
As shown in FIG. 9, the light-guiding member 203 is made of transparent synthetic resin and includes a light-incoming portion 203a positioned at the center of the supporting base of the upper case 201, and a light-guiding portion 203b which extends from one side of the light-incoming portion 203a and has one side disposed in the vicinity of and in opposing relationship to the side face which opposes the side face in which the openings of the recesses 206c of the slider member 206 are located. An opening 203c is formed so as to pass vertically through the center of the light-incoming portion 203a. A lighting lamp (not shown) is inserted into the opening 203c. The lighting lamp is fixed to the protrusion (not shown) which is formed to pass through a hole (not shown) formed on the circuit board 204 of the lower case 205, and protrudes from the hole of the circuit board 204.
Next, the illuminating state of the operating knob 202 of the mirror switch apparatus having such a construction in the case where the lighting lamp is lit will be described.
As shown in FIG. 7, when the operating knob 202 protruding from the top of the upper case 201 is in the neutral position, the slider member 206 is also positioned in the neutral position. The connector 206a is also positioned roughly in the central portion of the opening 201a. Accordingly, in the indicators 202b positioned on both sides of the knob portion 202a, the light from the lighting lamp passes through the light-guiding portion 203b from the light-incoming portion 203a of the light-guiding member 203, and illuminates the side face of the slider member 206 from the end of the light-guiding portion 203b. The light is reflected upward by the two reflecting surfaces 206d of the slider member 206, and illuminates the both of the indicators 202b from the opening 201a. Since both of the indicators 202b are bright in the neutral position, the driver can easily recognize that the operating knob 202 of the mirror switch apparatus is in the neutral position.
As shown in FIG. 8, when the operating knob 202 in the neutral position is moved toward the right, the movable contacts, accommodated in the right movable contact accommodating recess 206e, comes into contact with, for example, the right stationary contact of the two stationary contacts on the circuit board 204, whereby the right mirror driving motor is ready to be driven. At this time, as shown in FIG. 8, the right light-intercepting portion 201b, disposed below the right indicator 202b, comes between the operation knob 202 and the slider member 206 to shield the light path from light, causing the right indicator 202b of the operating knob 202 to become dark. On the other hand, since the left indicator 202b moves away from the left light-intercepting portion 201b and arrives above the opening 201a, light from the lighting lamp reflected by the left reflecting surface 206d of the slider member 206 reaches the left indicator 202b of the operating knob 202 to illuminate the left indicator 202b. Further, R indicating the right is formed on the left indicator 202b, and L indicating the left is formed on the right indicator.
The lighted switch apparatus according to the related art is configured so that the reflecting surface 206d of the slider member 206 is provided below the opening 201a the upper case 201, and light is led to the indicator 202b of the operation knob 202. Accordingly, there is a problem that the light leaks from the opening 201a by the operating the slider member 206. In addition, when the slider member 206 is positioned on both sides of moving path, the indicators 202b needs to form the opening 201a so as to face the reflecting surface 206d and area of the reflecting surface 206d needs to be set in consideration of the indicators 202b. For example, when the indicators 202b is set to be large, it is necessary to change the reflecting surface 206d and the opening 201a to be large, and to change the length of the light-intercepting portions 201b to be long. Accordingly, there is a problem that the manufacturing cost increases. Furthermore, for example, if the opening 201a does not need to be illuminated, even though the open opening 201a is formed in the size allowing the movement of the slider 206, there has been no problem. However, in case of the illuminating structure, it is necessary to make the space where at least two indicators 202b are formed. Consequently, there are times when the opening 201a is set to be large for the illuminating structure, and there is a problem that restriction of the structure to close the opening 201a becomes large.
In addition, both of the indicators 202b are illuminated in the neutral position of the operating knob 202, and one of the indicators 202b is illuminated in the distal position in which the operating knob 202 is move to the right or left side. For example, when both of the indicators 202b are illuminated in the distal position, it is conceivable that the light-intercepting portions 201b are removed. However, in this case, the opening 201a again becomes large and a part of the inside is seen from above to be an exposed state. Furthermore, since the side face (light outgoing face) of the light-guiding member 203 facing the slider member 206 is deviated, there is a problem that sufficient illumination intensity cannot be obtained. Moreover, since the illumination intensity of the indicators 202b is changed by the position of the operating knob 202, there is a problem that the operating knob does not look good.